Porous weldable metal structures are well known in the art. These structures may be formed by sintering metal particles or by laminating porous metal sheet material into a composite laminate. The structures may be joined one to another by welding processes. The size and shape of the porous metal structure may be limited by the method of manufacturing chosen. Joining discrete porous structures can be problematic because the structures are porous rather than uniform in density. The lack of uniform density in the structure together with the uniform application of welding energy can create a weld seam that is not uniform in weld penetration and/or weld seam width.
For applications requiring high uniformity in the permeability of the finished structure non-uniform weld seams can create performance issues in the finished product because of local variations in the permeability of the structure in and around the weld seams, and because of surface irregularities at the seam.
It is desired to provide a method for joining porous metal structures having a uniformly narrow weld seam that is generally free of surface irregularities.